


Slipping Into Madness

by DavidB1000



Category: Supergirl (TV 2015)
Genre: Cliche Comic Book Plots, Don't worry about Alex just yet, F/F, Gen, Good and Evil are Two Sides of the Same Coin, Infinite Mass Punch Is a Thing, Lena Gets A Surprise, Minor Character Death, Minor Humor, No That Pairing is Not a Typo, Not Major Violence, Red Kryptonite, Sanity Break, Set After Season 3, Violence, alex means well, fall from grace, so to speak, sort of., things get complicated
Language: English
Status: In-Progress
Published: 2019-01-07
Updated: 2019-01-24
Packaged: 2019-10-06 09:38:21
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 7,896
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17342945
Author URL: https://archiveofourown.org/users/DavidB1000/pseuds/DavidB1000
Summary: Alex Danvers gains Kara's powers by a freak accident at Lena's lab while working with her. Everything seems to go well until a single incident occurs and changes everything for the worse.Let me know if I need additional tags.Chapter 5 is now up!





	1. Diamonds Are Unbreakable

“No, no, no, no! This can't be happening!” Alex yelped.  
Lena grumbled. “I'm sorry my lab exploding on us was not something you wanted to happen.”   
She was trapped under a lot of rubble, but she felt that it's weight was not fatal to her yet. “Did my experiments involve the Scarecrow's fear gas somehow?” 

Alex groaned. “No, I'm sorry for freaking out. When I was younger I was involved in an accident that caused me to be trapped somewhere small and enclosed, and I just freaked out. I'm sorry.”

Lena nodded. “That's an understandable reaction honestly. It's fine. I'm sure Kara will come save us soon.”   
Alex frowned. “I know this whole relationship between you and Kara is strange to me. I nearly had a heart attack when she told me you knew she was Kara.”  
“We're friends, Alex. Not lovers.” Lena grinned.  
Alex laughed. “Okay, you have a good point there.”

“Though, to be fair, it is Supergirl! Who wouldn't want to hit that?” Lena giggled.  
“Okay, obviously, there is some Nitrous Oxide is around here.” Alex groaned.  
“Maybe it's like that time I got myself stoned by an experiment! That was hilarious.” Lena grinned.

Alex shifted her weight and frowned at how easily it was for her to move while something heavy was on her leg. She took a deep breath and yanked her foot back. The rubble on her leg flew into the air and landed several feet away. Her eyes widened and she stood up. “Okay. Wow. I feel so different.”

She shivered, and reached down and lifted up the rubble over Lena as easily as she had seen Kara do.   
Lena chuckled. “Apparently explosions in labs can give people super-human strength!”

“I'm not happy that we were working with Kryptonite, but you swore up and down you were helping Kara, and I trusted you.” Alex spoke.

“Exactly. I'm not a bad person.” Lena spoke.  
“I know that. I would have shot you by now otherwise!” Alex smirked.  
Lena grinned. “Okay. Fair enough. Well, get me out of the Nitrous and I probably won't laugh to death.”

Alex nodded. “Oh, boy. This is going to be one hell of a wild ride.”

&^&

3 weeks later...

 

“I knew I'd find you here.” Kara spoke.  
Alex frowned. “It's not fair.”

Kara nodded. “I know that.” She walked closer to Alex.  
Alex walked further away. “I don't want to see anyone. I don't want to talk to anyone.” 

Kara frowned and said nothing.  
Alex spoke again a moment later. “It wasn't supposed to happen like that. I didn't ever expect to do that. I can't go out. I'm sorry.”

Kara looked around the location they were in. “I know what happened was a horrible accident. No one blames you.”

“I blame myself. I didn't expect to lose control. I did not expect to get so upset when she showed up at my door.” Alex spoke.

“I know that.” Kara spoke.

“I just, I don't know why. But I hit her. I didn't mean to do it.” Alex shivered.

“No one expected Maggie to come back and no one expected her to come to your apartment like she did. No one would have expected her to be so cruel to you.” Kara spoke.

“I know. I just snapped. I didn't mean to.” Alex frowned. “She just laid into me as soon as I answered the door, and I just didn't understand why. She had been gone for so long. And then, everything just changed. I remember the impact, Kara. It was almost subconscious. I just had to get her to shut up. I didn't...” She trailed off.

Kara took a deep breath. “Alex, I promise you, no one hates you. We all understand what it's like to make horrible mistakes.”

“You never killed someone you once cared about!” Alex groaned. “That was so draining. I never thought I could lose myself.”

“It's okay, I promise you. Please, come back with me.” Kara spoke.

“Okay. We can go back.” Alex spoke after a moment of silence.   
“Thank you, because the sulfuric acid rain coming down is aggravating my nose.” Kara grinned.  
Alex chuckled. “Okay, I figured Venus was a good place to hide to get away from others.”

“It is. It's not the greatest planet, but some of the terrain reminds me of home.” Kara smiled.  
“Krypton had an ocean of CO2 at one point?” Alex grinned.

Kara laughed. “Not while life evolved on it! Maybe before. But Earth and Venus were a lot like it. Which is why Reign and those crazy Kryptonian witches tried to terraform the planet.”

“Okay, good point.” Alex nodded. “Let's go home.”

 

&^&

When they landed, it was at Kara's apartment. Alex was about to say something when she heard a voice speak. “Alex.” 

She turned and smiled. “Mom!”   
Eliza Danvers hugged her daughter and said. “It's okay, honey.”

Alex relaxed slightly. “I really didn't mean to do that.”  
“Hey, it's okay, Alex.” Kara spoke.

Eliza nodded. “You did not mean to do that. I can understand you weren't fully in control of all your powers yet. It would take time.”

“I was in control enough to go to Venus.” Alex frowned. “I just didn't know I would hurt someone.”  
“I understand that, dear.” Eliza hugged her again.

&^&

1 week later...

Alex looked around the graveyard. She saw no one, and walked closer to a grave. “I am so sorry.”   
She spoke while looking at it. She knew it wouldn't really help that much to say she was sorry to the grave, but she didn't know what else to do.

She frowned. “I know what I need to do, Maggie. I have to do the things Kara can't do. I need to kill the bad people to make up for what I did to you. It was so wrong to kill you.” 

She shivered, and jumped into the air and rushed off.

&^&

Several hours later...

Kara was starting to worry about Alex. Things had changed in her sister. She knew that. Her senses alerted her to an earthquake before humans could feel it. She frowned and rushed over.

She found Alex standing next to a crater in the ground. There was something resembling a pile of red goo in the middle of the crater.  
Alex groaned. “I didn't expect to hit hard enough to cause a localized earthquake.”

Kara winced, and walked closer. “Alex...what did you do?”

“I wanted to redeem myself for killing Maggie. So I tracked down someone that she had told me about, a criminal that she had never managed to get anything to stick to. Like John Gotti.” Alex spoke.

Kara looked down at the crater and examined the goo from a closer perspective. She winced, knowing what it was. “You can't do this, Alex.”

Alex shook her head. “I'm sorry, but I have to make up for what I did to Maggie, Kara.”  
“By killing people?! What would Eliza think?!” Kara gasped.

Alex winced. “She would hate this. I'm not an idiot. I just know what I need to do, Kara.”  
“You can't do this!” Kara spoke. “Please stop this. I can save you.”

“No.” Alex spoke and flew away.   
Kara grumbled and followed her. “You can't hide from me, Alex. We're the same.”

Alex turned around and shrugged. “I won't stop killing bad people just yet.” 

“Alex. Please. Stop this. I'm asking you nicely.” Kara spoke firmly.

“No.” Alex spoke and shoved Kara down towards the ground.

Kara grumbled and grabbed Alex and pushed her into the side of an abandoned building on the outskirts of National City. They crashed through and tumbled onto the ground. They both got back up a moment later and glared at each other.  
“You want to fight?” Alex grumbled. “I can fight.”

“I don't want to fight you! You're my sister, Alex. I just want to stop you from going too far.” Kara spoke.  
“You're not going to stop me!” Alex spoke and punched Kara backwards. “I don't even want to hurt you!” 

“Then stop punching me.” Kara spoke and punched Alex across the room again. “I don't want to hurt you. You cannot fight me here.” 

“I don't want to fight you, Kara! Just leave me alone!” Alex shouted.  
“No!” Kara spoke firmly.

“Then I'm going to smack you across the state!” Alex grumbled.  
“Alex. Please. I know it hurt you to kill Maggie like you did. It was a freak accident. She would not want you to do this.” Kara spoke softly.

Alex glared at Kara. “I promised her at her grave that I would freaking punish all the bad people to make up for what I did to her! I'm not going to go back on that!” 

Kara shook her head. “You're not going to convince me that this is what she wanted.”  
Alex spoke firmly. “Leave me alone, Kara. Let me do this.”

“No! I will not.” Kara spoke firmly.

Alex grumbled. “I won't stop, Kara. I will not stop. Until I know I am through with killing all the bad people.”   
“Please, Alex. I'm asking you nicely! Please, don't do this.” Kara spoke.

Alex shook her head. “I will not stop. I'm sorry, Kara.”   
Kara frowned. “I can't believe this is what it comes to, Alex. This is going to hurt me so much.”

“I know.” Alex spoke and punched Kara across the room.  
Kara grumbled as she slammed into the wall. “It's not fair.”   
“Leave me be!” Alex growled. “I don't want to hurt you!” 

“I can't let you kill people, Alex.” Kara spoke firmly.

Alex took a deep breath and headbutted Kara as hard as she could.  
Kara stumbled to the ground, dazed by the blow.   
Alex rushed away, trying to ignore the headache she was getting.

Kara recovered, grumbled unkind words under her breath, and rushed after Alex.  
She was going to have to knock out Alex, she knew that much.  
She saw Alex up ahead and slammed her fist into the small of Alex's back.   
The impact made Alex's eyes widen and slammed her hard towards the desert ground.  
Alex landed and made a small crater. She stood back up and glared at Kara. “Okay, fight me, bitch.”

“Geez. Alex. You're still my sister.” Kara frowned.  
“I'm not stopping here.” Alex spoke.

Kara winced. “Okay.” She slapped her hands together and blasted Alex a hundred feet away.  
Alex stumbled around for a moment, disorientated by the blast wave.  
Kara was relieved Alex did not have the resistance built up to that attack and at the same time saddened by the fact she was having to do this.

Kara rushed over and punched Alex numerous times in the head, finally making Alex pass out.  
“I'm so sorry, Alex.”

&^&

Alex woke up in a cell at the DEO. “WHAT?! Get me out of here!”

“No.” J'onn spoke with a hint of disappointment.  
“Fine, I won't kill people any more!” Alex grumbled.

“You're going to be in there until we find a way to calm you down.” J'onn spoke firmly.

Eliza walked over and glared at Alex. “I am very disappointed in you.”

“I don't care.” Alex frowned. “I want to save people by killing the bad people.”  
“That's not how this works, honey.” Eliza frowned.

“I don't want to make any more mistakes! I killed the woman I loved due to a freaking mistake! A moment of anger! I want to make up for that by killing only bad people!” Alex sobbed.

“Once we find a way to fix you, we will let you out.” J'onn spoke.  
Eliza frowned. “I'm sorry, honey. I'm truly sorry.”

Alex pounded on the window. “I don't know how much work it will take, but I will be free!”   
“You just need to calm down before you turn into Zod.” Kara grumbled as she walked up.

Alex snorted. “I don't want anyone to kneel before me!”   
“Regardless.” Kara spoke. “We only want you better.” 

Alex growled and turned around. “Leave me alone then!”

&^&

Several hours later...

A cough made Alex turn around again. When she saw who was standing in front of her cell, her eyes widened and she spoke. “Well, this is unexpected!”

The person grinned. “I know you didn't expect this, but let's just say it's hard to kill a Kryptonian.”   
Alex nodded. “I'm just surprised you're here. We don't have much in common.”

“Well, you know what they say. When you friends become your enemies, your enemies become your friends.” The person smirked.

“We'll go with that, Overgirl.” Alex spoke.

Overgirl smirked. “Believe me, this is going to get interesting.”   
“A Nazi and a Jew working together. This is the very definition of surreal.” Alex spoke.

Overgirl grinned. “It's not like I landed and just instantly fell into indoctrination land. I mean, my pod landed in 1919, so it was more like Hitler and company just found me first. He had friends back then, I mean, how else do you think Mein Kampf even got published?” She grinned.  
Alex chuckled slightly. “Okay, that makes sense. Now, get me out of here.   
Overgirl punched the window once and it shattered. Alex walked out, and Overgirl and her left quickly.

&^&

20 minutes later...

“What the hell do you mean Alex escaped?!” Kara grumbled.  
“She had help from Overgirl.” J'onn frowned.  
“Come again?” Winn blinked.  
Kara winced. “Why the hell would my evil Nazi twin help out a Jewish person? That's a little above and beyond logical.”

“I'm still confused how she's back. Didn't she explode?” Winn asked.  
“She clearly got better.” Kara groaned. “Look, I know how hard it is to kill a Kryptonian, but that would not be easy to recover from.”   
“Hell of a thing though.” Winn spoke.

&^&

As they landed on a hilltop, Overgirl stumbled. She grunted and stood back up a moment later.  
Alex frowned. “What's wrong?”

“I'm still weak.” Overgirl shivered. “It wasn't that long ago I was reformed from dust.”   
“How does that even work?” Alex asked, still surprised by all this.

“I'm not sure myself. I think part of the explosion I ended up as kept enough DNA strands around to keep the powers intact long enough to regrow me. Plus, yellow sun exposure.” Overgirl shrugged. 

Alex nodded. “Kryptonian biology is very strange under a yellow sun.”  
“Exactly!” Overgirl grinned. “So, let's just go from here. You want to stop the evil people, I'll help you.”

“If you're still weak, you'll need to not try to fight Kara.” Alex frowned.  
“I won't.” Overgirl spoke.

“So, now the question is, what should we do first. Once they learn you rescued me, they'll come down on us like a ton of bricks.” Alex frowned.

“We go to ground, as the old adage goes.” Overgirl smiled. “Trust me, I've still got friends from my world we can count on.” 

“Well, this could get interesting.” Alex spoke.  
“And hey, at least we won't try you at the International Criminal Court for shooting unarmed Nazis.” Overgirl grinned.

Alex grimaced. “Okay, I was a little kill happy then.”  
“Regardless, I've got a base set up even here, and it's where I spent a lot of my time recovering. Getting here was unpleasant, as well.” Overgirl frowned.

&^&

A short time later, Alex and Overgirl were inside an underground base.   
Alex looked around the main room. “This works for our purposes.”  
“You're not wrong.” Overgirl smiled. “This will help.”

“So, this is the big twist, huh?” A eerily familiar voice spoke.  
Alex's eyes widened and she turned to see Maggie. “What the?!”

Overgirl chuckled. “Not your Maggie, I'm afraid.”

Maggie grinned. “Earth-X Maggie Sawyer at your service.”   
“How does that even work?” Alex blinked.  
Overgirl smirked. “You know things weren't super different between our Earths.” 

“Okay, I'll just worry about this later. I wish I could still get drunk.” Alex frowned.  
“I'm sorry you killed your own Maggie Sawyer in a freak accident.” Overgirl spoke.

Alex frowned. “I wish I didn't, but it made me realize what I had to do. It's a shame no one else understands me. Other than you, of all people.” 

Overgirl put a hand on Alex's shoulder. “It's okay. I will help you.”   
“For that, I am indeed thankful for.” Alex smiled.

Maggie spoke. “Don't worry about me. I'll be here if you need me too.” 

“Thank you as well. I have a lot of questions about you.” Alex nodded.  
“I don't blame you.” Maggie grinned.


	2. Nightmare

**Summary for the Chapter:**

> Alex wakes up in bed with Overgirl, they make plans, Lena gets a shocking surprise, and Kara is tasked with a nearly impossible choice.

The next morning...

Alex woke up in a strange bed, and for a moment, she was disorientated. Then her memory kicked in and she frowned for a brief moment. She then realized she wasn't alone in the bed and looked down and blushed at the sleeping form of Overgirl lying next to her.

It was a surreal experience in a way to make love to someone almost 100 years old, despite looking only 25.  
Alex knew Kara hated talking about the ageless aspect of their powers, and Alex understood the reasons for that.  
Now though, Alex had Kara's powers, and was going to enjoy that aspect at the very least. Overgirl and Kara had so much in common, despite their differences, and Alex knew she was going to need all the help she could get if Kara tried to stop Alex again. She didn't want to fight Kara, and she knew Kara could fight dirty if she needed to. Something few people knew.

Overgirl stirred, woke up, and smiled. “Hey.”   
Alex looked down at the literal evil twin of Supergirl, and smiled. “Hello.”

“I need to sleep a lot more too, it's annoying. I'm used to not even needing sleep.” Overgirl frowned.

“Don't stress your body, you need to rest.” Alex spoke. “You literally exploded and got better. That would take a lot out of anyone.”

Overgirl nodded. “I know.” She frowned. “Don't worry, the place is shielded enough that no one will be able to get to us for a while.”

Alex spoke. “I'm glad. I think the best thing we can honestly do is to have you get Lena to help us. There's a good chance Kara did not tell her anything about you, so you can pretend to be Kara.”

“Wouldn't be too hard. We are literally the same, down to the gluons.” Overgirl grinned.  
“Behold, the Ubernerd.” Alex smirked.

Overgirl grinned. “You're not wrong.”

&^&

Lena looked up as Overgirl walked in through the large set of doors at L-Corp.  
“Hello, Kara.” Lena spoke.  
Overgirl looked down at her set of clothes that Alex told her Kara wore, and smiled. “Lena, hey, so, I need your help. I don't know if anyone told you about Alex.”

Lena frowned. “I'm sorry your sister had to be locked up.”   
“Well, about that, she escaped.” Overgirl spoke. “And I need your help.” 

Lena winced. “Oh, dear. An unfortunate time for me to dismantle all Lex's crazy destroy Superman weapons.”   
Overgirl grinned. “Regardless of your crazy brother, I believe you can help me. So, would you like to take a trip?”   
“As long as it doesn't involve that fake mustache you used to take me on a mustache ride, that made me laugh too much.” Lena grinned.

Overgirl nearly burst out laughing at the mental image she got and barely managed to hold it in. “Okay, Lena, let's not do the jumping on your face any time right yet.” 

“Please don't.” Lena grinned. 

&^&

A short time later, Lena landed at the secret base and looked around. “Well, this looks unique.”

“You haven't seen anything yet.” Maggie smirked as she walked out of the shadows.  
Lena's eyes widened. “What?!” 

Alex walked over a moment later. “I'm impressed, Lena.”  
“What the hell is going on here, Kara?” 

Overgirl smirked and blurred in place, revealing her normal costume a moment later.  
Lena's eyes widened and she gasped. “A Nazi Supergirl?!?”

“Overgirl at your service.” Overgirl smirked. “Nearly 100 years old, my pod landed in Germany in 1920. Raised by the Nazis, and Hitler. Then I became the leader of the Nazi empire. Letting a few people be the figurehead after Hitler's death in the late 80s.” 

“Why is Alex working with you?!” Lena gasped.

Alex shrugged and walked over to Overgirl and kissed her. “Love conquers all, Lena.”   
Overgirl smirked. “Not entirely wrong there.”

Lena grimaced. “I am so going to need a drink. Alex has become the most self-hating Jewish person ever.”  
Alex smirked. “Wow, Overgirl's the leader of the Nazi empire, and she's not even that mean.”

“I nuked New York with my heat vision.” Overgirl smirked.  
Alex groaned. “Okay. Good point.” 

Lena grimaced again. “So, I'm going to be the Lois Lane here, huh?”

Alex smirked. “Except you and her both can fight well. Regardless, Kara won't make a move on me while you're under the watchful eye of Overgirl. That way I can go and kill all the evil people.” 

“Stop this, please.” Lena spoke.  
“No, I am going to literally keep my promise to my Maggie.” Alex spoke firmly. “I am not going to stop until the evil people are all removed. Period.”

“Kara will stop you.” Lena spoke firmly.

“How? Even if she finds this place, she's not going to let you be burned to death just to stop me.” Alex spoke.

“If you kill me it will be a disgrace to Maggie's memory!” Lena spoke.

Alex rushed over and lifted Lena up off the ground with one hand. “Do not speak her name, Lena, until I deem you worthy of saying it.” 

She squeezed lightly, causing Lena's eyes to bulge out slightly.  
Alex dropped Lena a split second later, and Lena gasped and coughed.  
A moment later, she recovered and gasped. “Okay, sorry, but if you kill me, Kara will wipe you from the face of the Earth no matter the cost.”

Alex smirked. “Unless Kara is willing to destroy the Earth itself, I won't be killed by her. Regardless, you'll be safe for now..”

Overgirl smirked. “I can be very gentle.”  
Lena winced. “That comes across so wrong.”

“I know.” Overgirl chuckled. “I am a bad guy after all.”

Lena frowned. “Why can't I catch a break and have more creepy Daxamite old ladies who want to bang me?” 

Alex laughed. “Wow, you and Queen Rhea, really? Does Kara know?”

“Kara didn't freak out.” Lena frowned. “Look, I hate being the kidnapping victim, can you blame me.”

Maggie smirked. “I can't blame you for freaking out. Overgirl was the reason I didn't get killed for being gay.”

“I made it clear she could not be touched. She was the human who saved me when my world's Alex tried to kill me with a Kryptonite bullet.” Overgirl frowned.  
Alex winced. “Yeah, I can see my other self do that. Winn became a hardened general there, nothing like him here.”

Overgirl nodded. “There were so many changes, but there were so many similarities.

Lena frowned. “I just want you all to know, Kara can track me and will be here as soon as she can't find me.”

“I look forward to fighting her. I'll go out and you can stay here.”

&^&

Alex stood on the roof of the base Overgirl had, and looked around, waiting.  
It didn't take long before Kara landed before her, and frowned. “Please, stop this madness.” 

“Overgirl and I are together, and in this together as well.” Alex spoke firmly.

Kara blinked. “Okay, I wasn't expecting that. Look, you can't trust my evil Nazi twin!”

“I will, because unlike you, she knows I have to kill the bad people.” Alex spoke.  
Kara frowned. “I don't want to hurt you!”

“I know, but Lena is also hidden and under the protection of Overgirl. You try to stop me, and she kills Lena.” Alex growled.

Kara's eyes widened. “What's happened to you?!”

“I have to stop you from stopping me!” Alex spoke.  
“Don't do this. I can handle Overgirl.” Kara spoke. 

“You don't get this, Kara, you can't do both. You can't be in two places at once. You're not that fast yet.” Alex smirked. “Even Barry can't do that.”

“Please, don't do this.” Kara spoke.  
“I will not stop. I will cage myself in Kryptonite and whatever else you want, after all the bad people are gone.” Alex grumbled.

“This is insanity!” Kara gasped.  
Alex shook her head. “No. Leave me to do my things.”

Kara groaned. “I have to stop you, and I know Lena is here.”

“Make a choice then. Fight me, or fight Overgirl.” Alex smirked.

&^&

Kara phased through the ground and landed in the room where Lena was being held by Overgirl.  
“Leave her out of this.” Kara spoke firmly.

“I'm not even super angry you caused me to explode.” Overgirl smirked.   
“Just let Lena go.” Kara spoke firmly.  
“No.” Overgirl shrugged. “You're not going to win this time.” 

“I can beat you. Even now.” Kara spoke firmly.  
Overgirl smirked. “I've almost fully recovered, and I am older than you. I absorbed more sunlight than you did.”

Kara frowned. “I really don't want to hurt anyone, but to save Alex, I will do anything.”

Lena spoke. “Save your sister, not me. I can handle my own.”  
Overgirl smirked. “It's very simple, Kara. You have to make a choice. Stop your sister, or save Lena. It's up to you.”

Lena spoke. “She won't kill me, Kara.”  
Kara nodded. “That is true, but I don't know what to do here, Lena.”

**Notes for the Chapter:**

> How will Kara handle this? How will things go from here? Find out next time, same bat time, same bat channel! Wait...


	3. Deconstructionism

**Summary for the Chapter:**

> Kara goes and tries to talk sense into Alex after Lena tells her to, only to find out that Alex and Overgirl had planned for her interference. By using Red Kryptonite!   
> Which doesn't quite go the way Alex wanted.

“Looks like an impasse, Kara.” Overgirl grinned.  
Kara winced. “If you wanted to kill her, she'd be dead before I got here. I want to know your game-plan here? Get back at me by destroying my sister?” 

“I am not that pithy, nor is my tongue that good.” Overgirl smirked.

Kara grimaced. “Okay, after Lena told me about Queen Rhea and her, I don't think anything could have gotten weirder, but the leader of a Nazi Empire, and my Jewish foster sister, really?”

Overgirl smirked. “Regardless, I'm not going to kill Lena, because having you destroy the Earth with a single punch is not going to help me.”

“Leave my sister alone.” Kara spoke.  
“I'm not so evil that I can't love her.” Overgirl grinned. “We're the same as much as we are different. You and I know that.”

Kara winced. “I am aware of how similar we are.”   
Lena had been silent during the exchange, and finally spoke up. “Kara, I know how you are. I want you to go after your sister and talk sense into her.”

Kara frowned. “Okay, Lena. I will.” She rushed off.

Overgirl smiled. “And that was how I expected things to go.”

&^&

Kara found Alex hovering menacingly in front of a group of scared criminals.   
“Alex! Stop this.” Kara spoke.

Alex turned towards Kara and grinned. “Okay, Kara.”   
Kara winced. “Alex, this isn't fair.”

“No. It is. They are bad people. Therefor they must die!” Alex growled.

“Please, Alex, you're my sister! Don't do this!” Kara gasped out.

Alex smirked. “Why don't you tell them your home address while you're at it?”  
“I can erase their memories myself.” Kara spoke firmly. “Look, them knowing my name is Kara and you're my sister isn't a big enough deal! You need to stop this. You cannot kill people. What happens when you accidentally kill an innocent person?”

Alex frowned. “I would hate to do that, you're right.”  
“See? Please, Alex, come back to me. Come back to being good and nice, and just.” Kara spoke.

Alex frowned. “I just don't know. I made a horrible mistake, and I have to redeem myself by killing the bad people, Kara.”

“Alex.” Kara frowned. “I won't let you kill again.”

“How are you going to stop me?” Alex asked.  
“However I can.” Kara spoke.  
Alex frowned and in a blur of movement pulled something out of a pocket and pushed it against Kara's chest. Kara looked down at the familiar glow of Red Kryptonite and her eyes widened. The effect of the Red Kryptonite washed through Kara's body.  
Alex smirked. “Overgirl and I both knew you would choose at the end of the day to come after me. I had a sample of this from a long time ago, and I know what it does to you.”

Kara grinned a moment later. “Well. This is interesting.” She then backhanded Alex across the alleyway.  
Alex slammed into the wall hard and grunted. Kara chuckled. “Sorry, Alex, but Red Kryptonite isn't just going to turn me evil. You need Black Kryptonite for that. Now I just don't care if I have to beat you senseless!”

Alex grumbled. “Okay, Plan A failed.”   
Kara smirked. “Well, I mean, we can still have fun.”   
She picked up one of the crooks and threw him at Alex.  
Alex winced, caught the man, and put him back down.  
Kara smirked. “And you claimed you wanted to kill them.”

“Not like that.” Alex grumbled. “That's just tacky to have him compress himself by slamming into me.”  
Kara chuckled. “So, now that I'm free, I guess I'll just go Kenshiro, Fist of the North Star on you.” 

Alex rolled her eyes. “Oh, come on.”

Kara smirked, rushed over and punched Alex backwards, slamming her through the wall, landing her in the middle of a crowded room of people. Who all panicked.

Kara smirked. “Sorry, everyone, but I have to beat up Alex here.”  
Alex rolled her eyes and Kara punched her backwards even harder.  
Alex launched clear across the room she was in, and through the doorway.  
Kara walked through and smiled. “Okay, Alex, let's have fun.” 

Alex grumbled. “I have made some bad choices.”  
Kara grinned. “No shit, really?”

“Look, even if this doesn't turn you to our side, I know you won't want to hurt innocent people even on Red Kryptonite. So, please, just, work with me here. Let me go about and kill the bad people!”

Kara shook her head. “Red Kryptonite doesn't make me stop wanting to do good things, damnit.”  
“I can understand that, but please, Kara, don't fight me. I'm not as strong as you.” Alex spoke.

“Damn right, you're not. You've got a lot of work to be that strong.” Kara smirked.

Alex took a deep breath. “You know at the end of the day I'm not a bad person.”  
“I know that, which is why I need to stop you and your weird murder happy fun times.” Kara grinned.

“I don't want to hurt people, honestly, but I know I have to take care of the bad people.” Alex spoke.

Kara shook her head. “I'm stopping you.”   
Alex frowned. “You know Lena isn't going to like you like this.”

“Yeah, but I can voluntarily fix this on my own.” Kara smirked. “A little pain is fine.” 

“I don't want to stop what I am doing, Kara. I need to kill the bad people.” Alex spoke.

“Then I'll just beat you up again.” Kara smirked.  
Alex frowned. “This isn't far. Red Kryptonite should have made you like me and Overgirl1”

“I'm sorry your calculations failed badly.” Kara smirked.

Alex glared at Kara. “You know we have a plan B, right? In case of failure.”

“I believe you.” Kara nodded.  
“Better go talk to Lena again.” Alex spoke. “I know you'll want to.”

Kara frowned, and then rushed off.

&^&

Kara crashed through the roof instead of phasing through it, and landed in front of Overgirl and Lena.  
“What's your game, Overgirl?” Kara growled and her eyes flashed red.

Lena winced. “Alex gave you Red Kryptonite!?”

“Yes.” Kara grinned.

“The game, if you will, is quite simple. You go and let Alex murder the bad people, or I'll flood this room with Sarin Gas. You and I will be fine. Lena however, will be dead in seconds.” Overgirl smirked.

Kara growled and Lena winced.

**Notes for the Chapter:**

> Now how is Kara going to get out of this situation? It's not a pleasant one, and Overgirl isn't one to bluff. :)  
> When dealing with your evil twin, you always have to confront your own darkness.


	4. Armaggedon

**Summary for the Chapter:**

> Kara saves Lena, Overgirl and Alex plot, and Alex comes up with a plan that shocks Kara into an almost irrational anger.  
> Don't worry, it's not over yet!

“This is excessive, even for Nazis.” Lena spoke.  
Overgirl shrugged. “Hey, I'm evil, so sue me. Like I said, I'll release it if Kara doesn't leave Alex alone.” 

“I'll take Lena out of here faster than it can spread.” Kara grumbled.  
“You forget something. I'm almost back to full strength, and I have absorbed the sunlight for over 90 years. You've got less than 16 years in it.” Overgirl grinned. “It's not like I can lose a fight now.”

“I'll kick your ass so hard, you'll kiss the moons.” Kara grumbled.

Overgirl grinned. “You're not that strong yet, Kara. So, go, let Alex kill people.”  
Kara fumed in anger, and Lena spoke. “Kara. I trust you completely.”

Kara was silent for a moment, and then in a blur of movement, punched Overgirl across the room and through the solid concrete wall.  
The room echoed with the sound of the impact, and Lena's ears rang like a bell. She grabbed them and winced. “Kara, what the hell was that?!”

Kara shook her fist. “I know it won't last long, but that is long enough to get you to safety.”  
She rushed over and took Lena out of the room through the hole she had made.

&^&

When they landed on the roof of L-Corp, Lena shivered. “I have never felt or heard that kind of force before. How hard did you punch her?”

Kara looked at her hands and frowned. “I hate holding back, but I always have to. For her, though, I can dish out the pain if needed. I hit her at 99.99% the speed of light.”

Lena's eyes widened. “Holy hell, Kara, I honestly didn't know you could punch that hard.”  
“It's not something we do often. It's a tad bit dangerous. The room helped contain the impact force. I can control the effect of the punch around me, that's why you're okay.” Kara spoke and hugged Lena to her. “I love you, Lena, and I would never hurt you.”

Lena relaxed. “Still, that was a hell of a thing. You must have had an impact energy equivalent of the mass of the sun!”   
“Just about.” Kara grinned. “It is very dangerous, that is a lot of mass/energy equivalence.”

&^&

Alex looked up from the criminals she was about to remove from existence, as Overgirl landed before her, looking pissed. “She freaking infinite mass punched me!” Overgirl growled.  
“Uh. What?” Alex blinked.  
“What Barry named it in the future, according to Eobard. Supergirl punched me at almost the speed of light. Imagine someone punching you with the mass of the sun!” Overgirl grumbled.

Alex winced. “Ouch. Not only did our Red Kryptonite plans fail, she seems even more dangerous than she should.”

“We're going to have to use her goodness against her, and I really don't want to go and murder innocent people myself. Like I said, I didn't just suddenly become what I was.” Overgirl grumbled.

“I get that.” Alex spoke and hugged her. “Okay, let's regroup for now. We'll go and get her to leave us alone. I have a plan.” 

“Okay.” Overgirl frowned.

&^&

Kara was standing by Lena, protective as always, in the underground parking lot under L-Corp headquarters. “I'm sorry we've had to hide our relationship.” Kara spoke.

“It's quite fine. I think it's all out of the bag now though.” Lena grinned.  
“Yeah, I figure Alex would understand things now for certain.” Kara groaned.

Before she could finish, the ground shook violently. Lena stumbled slightly. “What in the world? There's no fault line near this city!”

Kara frowned. “That doesn't seem like a normal earthquake at all.”   
The ground shook again, and Kara winced. “I've got to go. Here, I'll take you to a safe place first.”

&^&

After depositing Lena on a hill near National City, Kara flew up into the air far above National City, and scanned everywhere around with her hearing and vision.   
She frowned as she could not find anything to support the recent earthquakes. She flew up even further, and still even more, until she floated in space, looking at the Earth below. She focused her vision and saw something shake the Earth as a whole. She winced and rushed to the location she saw it coming from.

She slammed into the ground a moment later, drilling down through rock, as far as she could, focusing on one spot in particular.  
She burst out into an open cave. She rushed forward quickly, and grabbed Alex. “What the hell are you doing?!” 

Alex smirked. “I'm glad the Earth moved for you too!”   
“Are you insane?! You can't just screw with tectonic plates!” Kara yelled.

“I wasn't screwing them, I was punching on one, causing it to slip and slide, so to speak.” Alex grinned. “I was making sure the earthquake wasn't that dangerous.” 

“You caused the entire Earth to shake from the last one! Even if it wasn't perceptible to human eyes!” Kara yelped.  
“Regardless, I'm not going to stop until I kill all the bad people. So, let me kill the bad people, or I will 'accidentally' break the continent in half.” Alex spoke.

“That will kill billions!” Kara growled and punched Alex in the face.  
Alex stumbled back from the blow. “Okay, someone is mad.” 

“You have to be stopped! That's not even the Red Kryptonite any more. I've shrugged it off! I just want to kick your ass for trying to destroy this planet!” Kara yelled.

“I'd rather not kill you, Kara, but if you don't leave me any choice, well, I can really mess you up.” Alex smirked.  
“How?” Kara frowned, confused.

“How long can a human survive in this area, here? This environment? This far beneath the Earth's crust?” Alex asked.

“A minute or two before the heat and pressure overwhelm them.” Kara frowned. “Why?”   
“Let's just say, I've got a magic bullet, so to speak.” Alex grinned.

“What made you like this? Overgirl isn't going to be happy with your insanity now!” Kara spoke.  
Alex smirked. “Regardless, I know exactly what I'm doing. You have to make the choice here. Let me kill the bad people...or well, everyone dies.” 

Kara groaned. “Fine, you want me to make a hard decision, how about I break your neck!”  
“Are you sure you're off the Red Kryptonite?!” Alex grinned.

“Yes.” Kara grumbled and grabbed Alex's head. “Please, don't make me do this.”  
“Don't make me do this.” Alex spoke and then Kara was aware of a sharp pain.  
She stumbled back from Alex and looked down as a golden knife blade stuck out of her stomach. “What?” Kara gasped and stumbled to the ground.

“Gold Kryptonite, Kara. Takes away your powers for a bit of time. Just enough time too.” Alex spoke. “You know I never really wanted to hurt you, Kara. But you wouldn't let me do what I needed to do. If it's any consolation, I will not hurt Lena ever. No matter what.” Alex spoke.

Kara groaned. “I can't believe you're doing this.”  
“Save your strength.” Alex spoke, and shot straight up, drilling through the roof of the cavern.   
Kara grunted as rock rained down on her.

“You can't do this!” Kara yelled.  
Alex punched the sides of the tunnel she was drilling as hard as she could. The ceiling of the cave collapsed. “Sorry, Kara, but I did.”

&^&

“Well, that was not how I expected things to go.” Overgirl frowned.  
“I didn't want to do it, either, but Kara left me no choice.” Alex frowned.

“You said she was going to break your neck?” Overgirl asked.  
“Yes.” Alex nodded.

“Very strange.” Overgirl frowned. “I wonder...”

**Notes for the Chapter:**

> Don't worry about Kara. She'll be fine. :)


	5. Doomsday

**Summary for the Chapter:**

> In this chapter, J'onn confronts Alex, Barry Allen arrives to talk sense into Alex, and Kara gets better! And at the end, Superman's plan is revealed.

3 days later...  
Alex chuckled as she landed before a large group of criminals hiding in a warehouse. “Gentlemen, it's like you didn't get the memo. I'm killing all the bad people in the world. Starting with this city.”

“Crap.” One of the men spoke.  
Alex grinned. “What are you, a Mormon? Anyhow, die!” 

“Stop this!” J'onn J'onzz spoke as he landed in front of Alex.

“Damnit, I buried Kara under millions of tons of rock, go rescue her!” Alex grumbled.

“I am aware of what you did to Kara. We're trying to reach her. I'm only here as a courtesy. The rest won't come as friends. Please, let me reach into your darkness, and pull you back.” J'onn spoke.

“No.” Alex spoke and unleashed her heat vision, setting J'onn on fire. J'onn screamed in agony, dropped to the ground and began smothering the flames.

“Good, you learned Stop, Drop, and Roll.” Alex smirked and turned back to the shocked criminals.   
“So, which one should I kill first.” Alex spoke.

“None of them!” A voice shouted.   
Alex blinked in surprise. She turned to see Barry Allen, The Flash, arrive.  
“Well, I did not expect this.” Alex smirked. “What do you expect to do? Appeal to my conscious?”   
“Stop this. Please!” Barry spoke. “You are too good to go down this path.”

“I am not going to stop. What do I have to do to get that point across? I'm not going to actually break the planet!” Alex grumbled.

Barry winced. “This is not what Kara would want.”   
“Kara is dead and buried under millions of tons of rock. I don't care what she wants.” Alex sneered.

Barry grimaced. “Please, I'm asking you very nicely, don't do this.”

“Oh, please, what are you going to do? Overgirl explained to me speedsters can't phase through a Kryptonian's body!” Alex smirked. “And I am now and forever a Kryptonian. I don't have any human weakness in my body! I don't even have Kara's weakness to glowing rocks! So, what the hell are you going to do to me, Barry Allen?” 

“You don't get it.” Barry frowned. “We're going to stop you, everyone. No matter what it takes.”  
“Go back to Iris, Barry, and leave this up to the Gods, not the mortals.” Alex smirked.

“You're not a God, Alex.” Barry winced.  
“And yet, you cannot defeat me.” Alex smirked.

“I just don't want to see you give up your humanity for an evil version of Kara.” Barry spoke.  
“Overgirl's tongue is not that amazing!” Alex grinned.

Barry blushed slightly. “Look, I know you hurt Kara, and I know you're on this quest to destroy all the evil, but this isn't how you should go about it.”

Alex shrugged. “I'm not stopping this.”  
“Then I will.” Barry spoke and rushed at Alex.  
Alex saw him coming and backhanded him across the room.  
He hit the ground hard. “Ow.”  
He got back up. “Look, obviously, you can see me in super-speed, I get that.”

“Don't mess with someone beyond you.” Alex spoke.

“Please, I'm asking you nicely. Don't do this.” Barry spoke.  
“No.” Alex spoke.   
Barry frowned, and moved forward as fast as he dared to go. He suddenly stopped as Alex suddenly held him by his throat. “Stop messing around, Barry.” Alex grinned.

“That was almost the speed of light!” Barry gasped. 

“Should have gone faster than light, then!” Alex smirked.  
“Put him down.” A voice spoke.

Alex grinned and dropped Barry. She turned around. “J'onn, I'm glad you recovered from the burning and the pain and the ow.” She smirked.

J'onn was not looking good, and he stumbled slightly. “You know I will die to save you, Alex.”

“I know.” Alex spoke. “You're too good. Don't worry, you can rest knowing the entire Green Martian race died with a bang, not a whimper.” 

“Please do not inflict Genocide!” Barry winced.

“He's the last living Green Martian.” Alex smirked. “I can't help that.”

“Please, Alex.” J'onn spoke.

“Ugh. I'm killing bad people! Why is everyone trying to stop me!?” Alex growled.

“Because you can't do this!” Barry spoke.  
“NO ONE TELLS ME WHAT I CAN DO!” Alex yelled, knocking everyone down with the shout.  
She jumped into the air. “Screw all of you.”

She rushed away.

&^&

“Alex needs to be stopped!” Winn spoke.  
It was two hours after Alex had left, and no one had heard anything about her. The room was getting crowded.

Superman frowned. “I agree. Extraction operations are going steady to clear up the rubble to get Kara, but it's not an easy task. Especially since I am here, but I cannot afford to let this city go unguarded for the time it would take even me to dig down there and get Kara.”

“Do we even know if Kara...” Winn winced and said. “Sorry.” 

“It depends on a lot of factors.” Superman spoke.   
“Alex said she killed her. I'm worried that she used Gold Kryptonite.” J'onn spoke.

Superman grimaced. “That is an unfortunate possibility. I am bringing in someone who I know can stop Alex if needed though.”

“Okay, that might help save J'onn from being killed. No offense, J'onn, boss, sir.” Winn gulped.

“It's okay, Winn.” J'onn spoke. “I heal quickly, even from fire damage.”

“Do we need to bring in a lot more people?” Barry asked, he had been silent until now.  
“Not just yet.” Superman spoke.

&^&

“The good guys won't let me catch a break!” Alex growled.

“That's why they're the good guys.” Overgirl chuckled.   
“Ugh. This is stupid. I need to kill the good guys I guess.” Alex grumbled.

“Well, you didn't want to do it, but they did make you.” Overgirl nodded.

“This is so annoying.” Alex frowned.

“For what it's worth, they'll be too busy fixing Kara.” Overgirl smirked. “To see our new plan. Let me tell you something important.” 

“It better not be, 'I'm pregnant.” Alex grinned.  
“Hahaha! No.” Overgirl laughed.

“Okay, so what is it?” Alex asked.  
Overgirl smiled. “It's a long story.

&^&

Kara groaned as the sunlight struck her face. She opened her eyes and realized she was not in her bed. “What?!” She stumbled to get up.

“Hey, take it easy, Kara.” A voice spoke.

Kara turned her head and saw Lena staring at her with a look of concern. “I've been beside myself for days, trying to get you back to us.” Lena smiled.

“What hit me?” Kara groaned. “Normally I remember everything, but a lot of stuff is blurry to me right now.” 

“You've been stabbed with Gold Kryptonite and buried under millions of tons of rock. Your memory being fuzzy is to be expected.” Lena smiled.  
“Ugh. No wonder I feel like I was hit by a truck made of Kryptonite.” Kara groaned.

“It's been over a week, by the way, since then.” Lena frowned.  
Kara winced. “Where's Alex? We need to stop her.”

“Whoa there, you need to rest still. You're not recovered yet. Superman has a plan for Alex if she shows up again.” Lena spoke.

“I'm surprised she's not going on a murder spree.” Kara groaned.  
“She's vanished, but she'll return soon I bet. Knowing Alex. As a Supervillain, she probably obeys the cliché rule about showing up when the good guys least expect it.” Lena grinned.

Kara chuckled weakly. “Okay. Can you get Superman, I want to talk to him.”

Lena nodded and walked out of the room. Kara grumbled slightly and stood up. “Wow. This is so weird. I never expected to fight Alex, and I never expected her to go as far as she did.” 

The door opened and Superman walked in a moment later. “Hello, Kara.”  
Kara walked over and hugged her cousin. “This whole event is absurd.”

“I agree.” Superman smiled.  
“Lena told me you have a plan for Alex?” Kara asked.  
“Yes, a very unorthodox plan.” Superman nodded.  
“What do you have in mind?” Kara asked.

“Doomsday.” Superman spoke firmly.

**Notes for the Chapter:**

> Surprise! What? Do you think I'd forget about Spiky Gray Guy? :P

**Author's Note:**

> It's only just begun. I've been working on this for a while, so I thought I'd put up the first chapter to see what people think.  
> Yeah, the pairing here might be unique, but as Overgirl states, it's not like she just fell straight into Indoctrination land. :)


End file.
